I have a question for you guys. I have both a rigger and a decker in my group, can the decker slave the rigger's RCC and then put 3 marks on a riggable device so that the rigger will be able to jump in to it?

In my game, absolutely.

I don't think so:

The Decker Persona has 3 Marks, but cannot jump into a device.

The Rigger Persona has no Marks on the Device, so it cannot jump in.

Synergy between Decker and Rigger is practicly non existing. The Decker can protect the Rigger from other deckers...

Unless I missed something, a slave does not inherit Marks from the master. However, if the decker has 3 Marks he can simply issue a command (Control Device) "invite Marks from the RCC" for the same effect.

You have to be the owner to invite marks, or at least convince the device you're the owner.

If the Decker has 1 mark on the owner of a drone, he could Spoof a Command to it to have it offer marks to his Rigger friend. The rigger could then jump into the drone as it would have permission from the owner to allow it.

For a facility protected by a host, that would mean getting at least 1 mark on the Spider in control of the host, which means first breaking into the host. For an average civilian's iVacuum or commuter car, that just means getting marks on the person's persona, which does require them to be on the matrix, not just AR, but does not require them to be in VR.

How can you have Marks on a Owner? the Owner is an abstract concept not a File or a Device.

You need one Mark on the owner (@Tycho: the owner's persona icon) to spoof a command from him -- but if you already have three on the device itself, you can just do a Control Device for the same effect.

I don't have my book handy, but I could have sworn this wasn't legal. Something to the effect that only an Owner can invite marks. The device itself isn't it's own owner, so control device doesn't let you invite marks. Having three marks isn't the same as ownership, as the book also compares ownership to 4 marks, but you can never get more than three marks.

That's why most discussions about inviting marks involve the Spoof Command instead of Control Device.

But I'm going off memory here, and I might have that wrong.

EDIT: Also there is an argument on the internet that Spoof Command and Invite Mark aren't compatible either, because only a Persona can invite a mark, so spoofing a command to a drone still leaves you with a drone (device, not persona) that can't invite marks to begin with.

The description of "Invite Mark" indeed says "Required Marks: owner". However, if the owner invites marks he must obviously be performing some action on the device, like clicking the "invite MARK from <id> button". That action should be available to anyone with full access to the device. In theory, the owner could have a special hardware dongle or other token which needs to be present whenever inviting marks, but that idea meshes rather poorly with the requirement that the matrix is supposed to be usable. "Hey, we need some marks from the camera in sector 7G, have somebody walk over and plug in the dongle, please".

So yeah, I guess this is RAI, possibly even ignoring stuff that does not fit, but that's how you need to handle the matrix rules unless you want a Stealth chip in every garage door opener

I would argue that the Invite Mark Action is Owner Only (though apparently an Owner can designate actors to grant such a request). The Matrix is highly secure, remember, and the new protocols support that. That is why Hackers use Brute Force and Hack on the Fly Actions, to gain their Marks. There is no need for Owner Level Access to devices or Hosts. Don't think that Any Hackers I have watched in Play (Or played myself) have EVER needed to have 4 marks (Owner Level Access) for anything.

Drones have never been more secure.